1. Field of the Invention
The present invention relates to a refueling apparatus and method, and more particularly, to a refueling apparatus and method that may simultaneously detect a condition of reactor core in reactor vessel and a fuel assembly in the reactor vessel.
2. Description of Related Art
In a liquid metal fast reactor such as a sodium-cooled fast reactor, refueling is performed by remote control in a closed fuel cycle. Since sodium is opaque and reactive with air, refueling may be performed while a cover of a reactor vessel is not open.
In a conventional art, an ultrasonograph is mounted in a reactor, and a refueling apparatus is transferred to a predetermined location of a core after detecting an obstacle on a core top. Accordingly, fuel assemblies are exchanged. An ultrasonic immersion sensor is generally used for testing upper portion of a reactor core top. Also, an immersion ultrasonic sensor may directly immerse an ultrasonic sensor into sodium for an ultrasonic examination.
However, a fuel assembly in a core may be deflected or may be extended by several mm due to high temperature and radiation. In a conventional art, since fuel assemblies are exchanged without information about the above-described location movement or deflection, safe handling of a fuel assembly may be compromised.
Also, in a conventional art, an immersion ultrasonic sensor and a scanner to operate the immersion ultrasonic sensor must be separately mounted in a nuclear reactor. The scanner is required to be removed after examination. Accordingly, an examination process is complex and a significant amount of time for examination is spent.
Also, an immersion ultrasonic sensor is contact with a high temperature, highly radioactive liquid metal. Thus, a life of an immersion ultrasonic sensor may be reduced.